package ProgramUtils;

import java.io.File;

import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.*;

import java.io.File;

import javax.swing.tree.TreeModel;

/**
 * The methods in this class allow the JTree component to traverse
 * the file system tree, and display the files and directories.
 **/
public class FileTreeModel implements TreeModel {
    // We specify the root directory when we create the model.
    protected File root;

    public FileTreeModel(File root) {
        this.root = root;
    }

    // The model knows how to return the root object of the tree

    public Object getRoot() {
        return root;
    }

    // Tell JTree whether an object in the tree is a leaf or not

    public boolean isLeaf(Object node) {
        return ((File)node).isFile();
    }

    // Tell JTree how many children a node has

    public int getChildCount(Object parent) {
        String[] children = ((File)parent).list();
        if (children == null)
            return 0;
        return children.length;
    }

    // Fetch any numbered child of a node for the JTree.
    // Our model returns File objects for all nodes in the tree.  The
    // JTree displays these by calling the File.toString() method.

    public Object getChild(Object parent, int index) {
        String[] children = ((File)parent).list();
        if ((children == null) || (index >= children.length))
            return null;
        return new File((File)parent, children[index]);
    }

    // Figure out a child's position in its parent node.

    public int getIndexOfChild(Object parent, Object child) {
        String[] children = ((File)parent).list();
        if (children == null)
            return -1;
        String childname = ((File)child).getName();
        for (int i = 0; i < children.length; i++) {
            if (childname.equals(children[i]))
                return i;
        }
        return -1;
    }

    // This method is only invoked by the JTree for editable trees.
    // This TreeModel does not allow editing, so we do not implement
    // this method.  The JTree editable property is false by default.

    public void valueForPathChanged(TreePath path, Object newvalue) {
    }

    // Since this is not an editable tree model, we never fire any events,
    // so we don't actually have to keep track of interested listeners.

    public void addTreeModelListener(TreeModelListener l) {
    }

    public void removeTreeModelListener(TreeModelListener l) {
    }
}
